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Structural basis for recognition of phosphodiester-containing lysosomal enzymes by the cation-independent mannose 6-phosphate receptor. Proc Natl Acad Sci U S A 2010 Jul 13;107(28):12493-8

Date

07/10/2010

Pubmed ID

20615935

Pubmed Central ID

PMC2906551

DOI

10.1073/pnas.1004232107

Scopus ID

2-s2.0-77955444897   30 Citations

Abstract

Mannose 6-phosphate (Man-6-P)-dependent trafficking is vital for normal development. The biogenesis of lysosomes, a major cellular site of protein, carbohydrate, and lipid catabolism, depends on the 300-kDa cation-independent Man-6-P receptor (CI-MPR) that transports newly synthesized acid hydrolases from the Golgi. The CI-MPR recognizes lysosomal enzymes bearing the Man-6-P modification, which arises by the addition of GlcNAc-1-phosphate to mannose residues and subsequent removal of GlcNAc by the uncovering enzyme (UCE). The CI-MPR also recognizes lysosomal enzymes that elude UCE maturation and instead display the Man-P-GlcNAc phosphodiester. This ability of the CI-MPR to target phosphodiester-containing enzymes ensures lysosomal delivery when UCE activity is deficient. The extracellular region of the CI-MPR is comprised of 15 repetitive domains and contains three distinct Man-6-P binding sites located in domains 3, 5, and 9, with only domain 5 exhibiting a marked preference for phosphodiester-containing lysosomal enzymes. To determine how the CI-MPR recognizes phosphodiesters, the structure of domain 5 was determined by NMR spectroscopy. Although domain 5 contains only three of the four disulfide bonds found in the other seven domains whose structures have been determined to date, it adopts the same fold consisting of a flattened beta-barrel. Structure determination of domain 5 bound to N-acetylglucosaminyl 6-phosphomethylmannoside, along with mutagenesis studies, revealed the residues involved in diester recognition, including Y679. These results show the mechanism by which the CI-MPR recognizes Man-P-GlcNAc-containing ligands and provides new avenues to investigate the role of phosphodiester-containing lysosomal enzymes in the biogenesis of lysosomes.

Author List

Olson LJ, Peterson FC, Castonguay A, Bohnsack RN, Kudo M, Gotschall RR, Canfield WM, Volkman BF, Dahms NM

Authors

Nancy M. Dahms PhD Professor in the Biochemistry department at Medical College of Wisconsin
Linda J. Olson PhD Assistant Professor in the Biochemistry department at Medical College of Wisconsin
Francis C. Peterson PhD Professor in the Biochemistry department at Medical College of Wisconsin
Brian F. Volkman PhD Professor in the Biochemistry department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Acetylglucosamine
Binding Sites
Carbohydrates
Cations
Golgi Apparatus
Humans
Hydrolases
Ligands
Lysosomes
Mannosephosphates
Phosphoric Diester Hydrolases
Receptor, IGF Type 2
Receptors, Somatomedin
jenkins-FCD Prod-444 eb4ebd1a08581aba961d3befd3b851a3c3ec6b46